Ultrasonic Testing Analysis of Concrete Structure Based on S Transform

Xu, Juncai; Wei, Hai

doi:10.1155/2019/2693141

Cited by 19 publications

(17 citation statements)

References 26 publications

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“…Benamma et al [ 32 ] proposed a new modified S-transform based on thresholding technique in order to get a better time frequency resolution. Xu [ 33 ] used the frequency energy spectrum with S transform to identify defects in the concrete structure. Zhu et al [ 34 ] proposed a denoising algorithm based on the generalized S transform and singular value decomposition (SVD) to denoise echo signals of ultrasonic pulse-echo testing.…”

Section: Introductionmentioning

confidence: 99%

High Precision Detection Method for Delamination Defects in Carbon Fiber Composite Laminates Based on Ultrasonic Technique and Signal Correlation Algorithm

Cao

Jiang

et al. 2020

Materials

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This paper presents a method based on signal correlation to detect delamination defects of widely used carbon fiber reinforced plastic with high precision and a convenient process. The objective of it consists in distinguishing defect and non-defect signals and presenting the depth and size of defects by image. A necessary reference signal is generated from the non-defect area by using autocorrelation theory firstly. Through the correlation calculation results, the defect signal and non-defect signal are distinguished by using Euclidean distance. In order to get more accurate time-of-flight, cubic spline interpolation is introduced. In practical automatic ultrasonic A-scan signal processing, signal correlation provide a new way to avoid problems such as signal peak tracking and complex gate setting. Finally, the detection results of a carbon fiber laminate with artificial delamination through ultrasonic phased array C-scan acquired from Olympus OmniScan MX2 and this proposed algorithm are compared, which showing that this proposed algorithm performs well in defect shape presentation and location calculation. The experiment shows that the defect size error is less than 4%, the depth error less than 3%. Compared with ultrasonic C-scan method, this proposed method needs less inspector’s prior-knowledge, which can lead to advantages in automatic ultrasonic testing.

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Section: Introductionmentioning

confidence: 99%

High Precision Detection Method for Delamination Defects in Carbon Fiber Composite Laminates Based on Ultrasonic Technique and Signal Correlation Algorithm

Cao

Jiang

et al. 2020

Materials

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“…Both the material structural continuity and density determine ultrasonic wave velocity in materials: the structural damages disturb propagation of ultrasonic wave and decrease its velocity. The ultrasonic wave in material with defects reflect, refract, and diffract, which will lead to changes (decreases) in the propagation velocity of the ultrasonic waves [ 26 , 27 ].…”

Section: Resultsmentioning

confidence: 99%

Effect of Hollow Corundum Microspheres Additive on Physical and Mechanical Properties and Thermal Shock Resistance Behavior of Bauxite Based Refractory Castable

et al. 2021

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This paper analyses the effect of hollow corundum microspheres (HCM) on both physical-mechanical properties (density, ultrasonic pulse velocity, modulus of elasticity, and compressive strength) and thermal shock resistance behavior of refractory medium cement castable with bauxite aggregate. Moreover, the scanning electron microscopy (SEM) results of HCM and refractory castable samples are presented in the paper. It was found that the replacement of bauxite of 0–0.1 mm fraction by HCM (2.5%, 5%, and 10% by weight of dry mix) had no significant effect on the density and compressive strength of castable, while the modulus of elasticity decreased by 15%. Ultrasonic pulse velocity (Vup) values and the visual analysis of the samples after thermal cycling showed that a small amount of HCM in composition of refractory castable could reduce the formation and propagation of cracks and thus increase its thermal shock resistance.

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“…The same downward trend was observed in UPV test results (Figure 2). It is known, that structural damages or pores disturb the propagation of ultrasonic wave and decrease its velocity; also, ultrasonic waves pass slower in crystalline structures than in amorphous structures [35]. It can be assumed, that larger PVA fibers distributed in lightweight composites with GEG create more pores between the granules, which reduces the density of the composite and the UPV (Figure 3).…”

Section: Density and Upvmentioning

confidence: 99%

Modification of the Structure and Properties of Lightweight Cement Composite with PVA Fibers

et al. 2021

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This study addresses the application of polyvinyl alcohol (PVA) fibers to improve the performance of lightweight cement composites with pozzolans. Blended cement mixes based on expanded glass granules were modified with PVA fibers (Type A: Ø40 µm, L = 8 mm and Type B: Ø200 µm, L = 12 mm). The following research methods were used to analyse the effect of the fibers on the structure of cement matrix and physical-mechanical properties of lightweight composite: SEM, XRD, DTG, calorimetry tests, and standard test methods of physical and mechanical properties. Results from the tests showed that a denser layer of hydrates was formed around the PVA fiber and the amounts of portlandite, CSH, and CASH formed in the specimens with PVA were found to be higher. PVA fibers of Type A accelerated hydration of the cement paste, slightly increased the compressive strength of the lightweight composite, but had no significant effect on the values of density, ultrasonic pulse velocity and flexural strength. The shrinkage of cement composite was significantly reduced using both types of PVA fiber and both types of PVA fibers increased the fracture energy of lightweight cement composite with expanded granules.

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Ultrasonic Testing Analysis of Concrete Structure Based on S Transform

Cited by 19 publications

References 26 publications

High Precision Detection Method for Delamination Defects in Carbon Fiber Composite Laminates Based on Ultrasonic Technique and Signal Correlation Algorithm

High Precision Detection Method for Delamination Defects in Carbon Fiber Composite Laminates Based on Ultrasonic Technique and Signal Correlation Algorithm

Effect of Hollow Corundum Microspheres Additive on Physical and Mechanical Properties and Thermal Shock Resistance Behavior of Bauxite Based Refractory Castable

Modification of the Structure and Properties of Lightweight Cement Composite with PVA Fibers

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